Automatic block apparatus for electric tramways and railways



lgfigg 17 Patented Aug. 1,1922.

D. SAMAIA.

AUTOMATIC BLOCK APPARATUS FOR ELECTRIC TRAMWAYS AND RAILWAYS.

' APPLICATION FILED DEC.30, 1919.

DINO SAIVIAIA, OF MILAN, ITALY.

Specification of Letters Patent.

Patented Aug, 1, 19220 Application filed December 30, 1919. Serial No.348,426.

T 0 all whom it may concern:

Be it known that I, DINO SAMAIA, a sub ject of the King of Italy,residing at No. 57 Foro Bonaparte, Milan, Italy, have invented certainnew and useful Improvements in Automatic Block Apparatus for ElectricTramways and Railways, of which the following is a Specification.

This invention has for its object to provide an improved block apparatusfor electric tramways and railways.

The improved apparatus is so designed that the entry of one or morevehicles into a given section will bring into operation a numberingdevice that will signal the number of vehicles that have entered thesaid section, said device being returned into its initial position orposition of rest only when an equal number of vehicles has left the saidsection.

As shown in the accompanying drawing which illustrates by way of examplean embodime'nt of this invention The improved apparatus comprises asolenoid 1 whose core is excited each time a vehicle enters the section,and a solenoid 2 whose core is excited each time a vehicle leaves thesaid section. The core 3 of each of the said solenoids is connected atits inner end to a spiral spring 1, whereasits outer end is engaged bymeans of a stud 5 with a buttonhole slot 6 formed in one of the ends ofa rocking beam 7. The opposite end of this rocking beam which has theform of a fork 8, engages with a stud 9 fixed to a rack 10 havingratchet teeth.

Between the two racks there is arranged so as to slide in a guide 11, asupport 12 carrying a pin 18 on which is mounted a ratchet toothed wheel15 meshing with the racks 10; the rotation of this wheel is controlledby a pawl 16.

17 are spring stops or buii'ers serving to keep the racks 10 appliedelastically with their teeth against the teeth of the wheel 15.

A rod 18 adapted to slide in a guide, abuts with its inner end againstthe head of the support 12, its outer end being pivoted to a lever 19that is controlled bv a spring stop or buffer 20. This lever 19 with itscarbon contact A and opposing contact -B, acts as an interrupter in theblocking and unblocking signalling circuit, as well as for the circuitof a series of progressively numbered lamps 21. The contact block A isconnected to the current conductor C while the contact B is connected tothe signalling line or circuit D. The lamps 21 are not illustrated indetail in the drawing as they may be of any appropriate type, and itwill be understood that these lamps and the attachments therefor areindicated jointly by the numeral 21. The lamps are numberedprogressively in the same manner as the contacts by which their lightingis controlled, thus to the contact 23 identified by the numeral 1 willcorrespond a lamp numbered 1, to the contact numbered 2 a lamp numbered2 and so on.

To distribute the current to the said lamps 21 (as soon as the lever 19closes the circuit), there is provided a distributing ring 22 which hasupon its annular surface contacts 23 corresponding to the numbered lamps21. Concentrically to the ring 22 there is mounted upon a pin 24 atoothed wheel 25 (indicated by a dotted circle in the drawing) carryinga pointer 26 pivotally mounted on the same center as the toothed wheel25 and designed to close the circuit through the contacts 23. The wheel25 is actuated by a pitch chain 2'?" passing over rollers 28 and 29.This chain is fixed stone of its points to the sliding support 12. Thepointer 26 is electrically connected to the earth as indicated at E sothat every time the pointer bears against one of the contacts 23 of thedistributing rin the corresponding lamp 21 will be lighted.

The'operation of the improved apparatus is as follows YVhen, on theentry of a vehicle on to the section, the block solenoid 1 is excited,the attraction of its core 3 has the result of actuating the rockingbeam 7 by means of the stud 5 engaged in the slot 6. The forked end S ofthe rocking beam 7 acts in its turn upon the rack 10, causing the latterto move to the left one tooth, which is possible owing to the toothedwheel 15 not being moved, due to the elasticity of the stops 1? and thepeculiar shape of the teeth of the rack.

As soon as the solenoid has ceased to be excited, the spiral spring 4pushes back the core 3, thus returning the rocking beam 7 and the rack10 into their original positions. The rack 10 is thus brought again fromleft towards the right acting by means of its teeth upon the toothedwheel 15 which is caused to turn about its pivot 13 and at the same timeto ride upon the teeth of the opposite rack 10, since this latter doesnot move lamps 21.

owing to the fact that the pressure exerted by the wheel 15 is such asnot to overcome the pressure of the elastic stops 17 The result is thatas the pivot 13 ofthe toothed wheel 15 is fixed to the sliding support12,

the latter is also shifted towards the right. In consequence of thismovement of the support 12, the rod 18 with interrupter 19 is movedunder the action of the spring stop 20. The contacts A and B therebyclose the signalling circuit and alsothe circuitof the At the same'timethe action ex erted upon the pitch chain 27 by the move ment of thesupport 12 has the result of causing the wheel 25 to rotate, and causingthe pointer 26 to close the circuit through the contact corresponding tothe first lamp of the series of lamps 21. It is obvious that on theentry of a second vehicle on to the section, the same actions will berepeated and the circuit will be closed through the second lamp of theseries, and so on. i

For de-blocking, the operations are the same but in reversed order asfor blocking, until the support 12 again presses against the rod 18 andcauses the lever 19 with contact A to move away from contact B, andconsequently effect the V interruption of the circuit. .In operation, iffor instance, five cars have entered the section and the wheel 15together with the support 12 have been moved by the distance of fiveteeth of the rack 10 on the block side and the pointer 26 has inconsequence been successively brought from the contact 1 correspondingto the lamp 1 to the contact 5 corresponding to the lamp 5, then thesaid five cars leave the section which will result that wheel 15together with the support 12 will be moved for the distance of fiveteeth of the rack 10 and consequently the pointer 26 will be returnedfrom the contact 5 to its initial zero position. Evidently when thesupport 12 bears against the rod 18 the contact A of the lever 19 ismoved away from the contact D and the signalling circuit is interrupted.7

It is to be noted that in the case of a simultaneous excitation of thetwo solenoids 1 and 2, that is to say, where a vehicle should happen toenter the section at the same instant that another vehicle is leavingthe said section, the wheel 15. will revolve on its own axis withoutaffecting the support 12 and consequently without producing anysignalling.

The rocking beams 7 each comprise anose 30 which projects into a slot inthe core 8. This nose is designed to. move the contact 31 that alsoprojects into the said slot away each time the core of the respectivesolenoid has been sucked in. This has the result of inserting aresistance into the circuit of the solenoid for the purpose. ofpreventing an excessive heating in the case of a too prolongedexcitation;

The improved block apparatus is described hereinabove in its applicationto a system of light signalling, but it is obvious that it is applicablelikewise to all signalling systems.

What I claim is 1 1. In automatic block apparatus for electric tramwaysand railways, the combination of a blocking solenoid, whereof the coreis attracted each time a vehicle enters'the block section, a de-blockingsolenoid where of the core is attracted each time a vehicle leaves saidblock section, a toothed wheel,

racks meshing with said toothed wheel,

rocking beams acting upon said racks, connections between said cores andsaid rocking beams, a support carrying said toothed wheel, slidablebetween said racks, a series of progressively numbered electric lamps,circuits supplying current to said lamps, a distributor controlling thesupply circuits of said lamps, and means for energizing said solenoids,whereby each time a vehicle enters or leaves said block section, saidsupport is actuated by the corresponding solenoid core to operate saiddistributor in such a manner as to light up or extinguish the lampshowing the number of the vehicles in saidblock section. i

2. In automatic block apparatus for elec tric tramways and railways, thecombination of a blocking solenoid, whereof the core is attracted eachtime a vehicle enters'the block section, a de-blocking solenoid whereofthe core is attracted each time a vehicle leaves said block section, atoothed wheel, racks meshing with said toothed wheel, rocking beamsacting upon said racks,

connections between said cores and said rocking beams, a supportcarrying said toothed wheel, slidable between said racks, a series ofprogressively numbered electric lamps, circuits supplying current tosaid lamps,

a distributor controlling the supply circuits of said lamps, means forenergizing said solenoids, whereby each time a vehicle enters or leavessaid block section, said support is actuated by the correspondingsolenoid core to operate said distributor in such a manner as to lightup or extinguish the lamp showing the number of the vehicles in saidblock section, said toothed wheel being so constructed and mounted thaton a vehicle entering said block section at the same instant as avehicle is leaving said block section, said toothed wheel will revolveidly without affecting said support, and no signal will be given.

In testimony whereof I have signed my name to this specification.

DINO SAMAIA.

